Speed is the calling card of the best defensive players in FCS college football -- they fly around the field to create havoc on a regular basis.
In the 2018 season, look for them in the backfields of their opponents.
Here's a look at the most dominating defensive players by FCS conference:
Josh Buss, Montana, OLB, R-Sr., 6-2, 220
A two-time defensive MVP at Montana, Buss has racked up 33.5 tackles for a loss and 12 sacks in the last two seasons. He could be an All-American as a senior -- an accolade he earned playing lacrosse in high school.
Two More to Fear: Sacramento State safety Mister Harriel and North Dakota cornerback Deion Harris (note: UND games only count for opponents in the Big Sky standings this year)
Bryson Armstrong, Kennesaw State, LB, R-So., 5-11, 205
Last season, Armstrong was the first defensive player to earn the Jerry Rice Award (which began in 2011) for FCS freshman of the year. He regularly filled box scores, collecting 114 tackles, 11 sacks and seven takeaways as a rookie.
Two More to Fear: Charleston Southern defensive end/outside linebacker Solomon Brown and Campbell defensive end Emmanuel Olenga
Warren Messer, Elon, MLB, Sr., 5-11, 230
Messer got off to a dominating start as a tackle machine when Elon was one of the bigger surprises in the FCS last season. He ranked second in the CAA with 9.5 stops per game.
Two More to Fear: Richmond defensive tackle Andrew Clyde and James Madison cornerback Rashad Robinson
Nick Miller, Penn, LB, Sr., 5-11, 215
The runner-up for Ivy League defensive player of the year is coming off the most tackles (a league-high 104) by a Penn player in 20 years. He was one of eight FCS players to share the national high with four fumble recoveries, and he did so in the fewest games (10).
Two More to Fear: Princeton defensive lineman Kurt Holuba and Dartmouth linebacker Jack Traynor
Davanta Reynolds, North Carolina Central, S, R-Sr., 5-10, 200
Finally healthy for a full season, Reynolds was a big-play artist as a junior. He tied for second in the FCS with a MEAC-high six interceptions for 141 return yards, and he also had an 85-yard fumble return for a touchdown.
Two More to Fear: North Carolina A&T defensive end Darryl Johnson and Morgan State linebacker Rico Kennedy
Christian Rozeboom, South Dakota State, MLB, R-Jr., 6-2, 230
While SDSU posted its two deepest playoff runs in its FCS history, Rozeboom led the team in tackles with 132 as a freshman and 127 as a sophomore. He has 14 games of at least 10 tackles.
Two More to Fear: South Dakota defensive end Darin Greenfield and North Dakota State safety Robbie Grimsley
Thomas Costigan, Bryant, LB, Sr., 6-2, 230
The 2017 NEC defensive player of the year saved his best games for Bryant's biggest games. He became the second player in school history to post more than 100 tackles (103) and tied for the conference lead with 11.5 sacks.
Two More to Fear: Bryant defensive end Dillon Guthro and Duquesne strong safety Abner Roberts
Marlon Bridges, Jacksonville State, FS, R-Jr., 6-0, 200
The hard-hitting Bridges is one of the best in the FCS at forcing turnovers (he has 12 takeaways in two seasons). He was the Ohio Valley's 2016 freshman of the year and has made the all-conference first team twice.
Two More to Fear: Austin Peay linebacker Gunnar Scholato and defensive end Jaison Williams
Nick Wheeler, Colgate, DE, Jr., 6-2, 245
Patriot League teams can't be happy they have to defend Wheeler for two more seasons. Using speed and power, he led the league with 11.5 sacks and 15.5 tackles for a loss as a sophomore.
Two More to Fear: Fordham cornerback Dylan Mabin and Georgetown defensive tackle Kristian Tate
Willie Barrett, Marist, OLB, R-Sr., 5-11, 227
In a league which lost many of its best defensive players, Barrett is the returning rock, having advanced from the All-PFL second team in 2016 to the first team last year. He's versatile with productivity against the run or the pass.
Two More to Fear: Stetson cornerback J.J. Henderson and Dayton defensive end Nick Surges
Ahmad Gooden, Samford, DE, R-Sr., 6-1, 240
Gooden has been a standout for three seasons, earning the SoCon defensive player of the year award last season. He tied for second in the conference in tackles for a loss (15.5), tied for fourth in sacks (5.5), and tied for fifth in tackles (101).
Two More to Fear: Wofford defensive lineman Miles Brown and Western Carolina safety Marvin Tillman
Chris Terrell, Central Arkansas, DE, Jr., 6-2, 266
With good size, Terrell is a force coming around the edge. As a sophomore, he ranked among the national leaders in sacks (11) and tackles for a loss (20).
Two More to Fear: Nicholls defensive end Sully Laiche and Sam Houston State defensive end Chris Stewart
De'Arius Christmas, Grambling State, LB, Sr., 5-10, 220
A former player at East Mississippi Community College -- the famed Last Chance U -- Christmas won the SWAC defensive player of the year award last season. He was a wrecking crew with 16.5 tackles for a loss.
Two More to Fear: Grambling State defensive end La'Allan Clark and Alabama A&M DE Vernon Moland
-- Written by Craig Haley, who is part of the Athlon Contributor Network. Haley has covered the FCS level since 1999 and is the national writer for www.fcs.football. He appears frequently on radio shows and podcasts to discuss everything FCS. Follow him on Twitter @CraigHaley.
(Photo courtesy Elon Athletics)